Heat-resisting alloy



UNITED STATES P ATENT -OFFICE.

JOHN mennxnniz, on CLEVELAND, orrio, ASSIGNOR o THE CLEVELAND BRASS MANUFACTURING COMPANY, or CLEVELAND, OHIO, A CORPORATION or OHIO.

HEAT-RESISTIN'G ALLOY.

No Drawing.

To all it may concern Be it known that 1, JOHN T. Grumman, a citizen of the United States, residing at Cle'velano}5 in the county of Cuyahoga and State of hio, have invented a certain new and useful Improvement in Heat-Resisting Alloys, of which the following is a full, clear, and exact description.

The present invention relates to an alloy, which due to its inherent physical and chemical properties forms a highly desirable and efiicient metal for use in constructing articles which are to-be used under certain conditions.

Among the important properties of th alloy the following may be stated:

1. The alloy willwithstand repeated heating to high temperature without appreciable deterioration.

2. The surfaceof the article which is made of the alloy is not subject to scaling, nor even after repeated heating and cooling is ,there any warping, cracking or deformation.

3. The alloy is resistant to corrosion .due to' Contact with corroding substances or fumes such as corrosive liquids or solids or oxidizing gases.

4. The alloy has a high melting point so that thearticle which is made of the alloy may be subjected to considerable heat without in any way endangering the structure of the article due to melting or fusing.

5. Articles or parts of structures made from the alloy of the present invention do not grow or increase in size even after repeated heatings, that is to say, they do not increase their dimensions.

The alloy forming the subject of this invention is eminently adapted for the making of containers or boxes for heat treating or oarbonizing purposes, sagga'rs, furnace parts, crucibles, glass molds, metal molds for foundry use, retorts, dies, die rings,--in fact, any structure where the important proper ties of the alloy may be utilized. The alloy also may be utilized for the manufacture of electrical resistance elements.

The alloy consists essentially of a combination of chromium, nickel and iron, although there will usually appear in the final alloy some silicon and some manganese, and perchance a trace of titanium.

As is very well known, silicon and titanium are commonly used and added to a bath of molten metal for deoxidizing and.

Specification of Letters Iatent. Patented Aug, 30, 1921, Application filed January 14, 1920. Serial No. 351 441.

' scavenging purposes, and in the present instance their use is limited to this feature, but small amounts of the metals mentioned maybe-found in the final-alloy due to the desire to insure the presence of sufficient silicon and titanium to accomplish the purposes desired.

The manganese is added to the molten metal for the purpose of giving a good grain to the alloy,.and also for the purpose of preventing the formation of graphitic carbon, the manganese tending to cause the carbon present to appear in the final alloy as carbid of iron and chromium.

The alloy contains 15 to 40 per cent. of chromium, 1 to 15 per cent. of nickel, with the balance consisting substantially of iron, except as before noted, the presence of slight amounts of silicon and from 1}- of 1 per cent. to 2 per cent. of manganese.

The carbon in the final alloy is maintained as low as possible, preferably as low as of a per cent. although the carbon may run as high as 2 per cent. The desirability of having the low percentage of carbon lies in the fact that the final alloy is less brittle, and when the carbon is as low as 1 per cent. or under, articles made from the alloy are quite readily machined.

As an example of a typical analysis of an alloy found to contain the desirable quali\ ties, the following may be given:

Chromium, 18 per cent.

Nickel, 4: per cent.

Silicon, .48 per cent.

Titanium, .2 per cent.

Manganese, 1 per cent.

Carbon, 1 per cent.

Iron, balance.

- The chromium present imparts the highly resistant qualities as to long wear and noncorrosion as well as the property of nonwarping. i

The nickel renders the alloy more homogeneous and less likely to crack when subjected to repeated heatings.

The manganese, as'before stated, gives a good grain to the alloy and tends to main tain the carbon present in the final alloy in carbid form.

The final alloy obtained is'a metal which may be easily handled in the foundry and can be cast in precisely the same manner and by' the same methods as are at present commonly employed in foundry practice.

The alloy has a high tensile strength, is

tough and resistant to breakage. Where the- The alloy is preferably produced in the electric furnace by melting commercial ferrochrome together with the desired quantity of low carbon ferrous scrap material and with suitable fluxes for dephosphorizing, if such a. flux is necessary, and suitable fluxes for desulfurizing.

The silicon and titanium are added to the molten alloy just before pouring, and as before stated, are used for the purpose of deoxidizing and scavenging the metal from occluded gases.

Having described my invention, I claim:

1. An alloy which is substantiallynonwarping and nonoxidizing at high temperatures containing as essential ingredients substantially 15 to 40 per cent. of chromium, substantially 1 to 15 per cent. of nickel, the balance consisting principally of iron.

2. An alloy which is substantially nonwarping and nonoxidizing at high temperatures containing as essential ingredients sub stantiall 15 to 40 per cent. of chromium, substantially l to 15 per cent. of nickel, carbon up to 2 per cent, the balance consisting principally of iron.

3. An alloy which is substantially nonwarp-ing and nonoxidizing at high temperatures consisting of substantially 18 per cent.

of chromium, 4 per cent. of nickel, the balance consisting principally of iron and carbon.

In testimony whereof I hereunto a-fiix my signature.

JOHN T. GLEKLER. 

